The Federal Aviation Administration recommended late Sunday that airlines begin visual inspections of door plugs installed on Boeing 737-900ER planes, the second Boeing model to come under scrutiny this month.
The FAA said the plane has the same door panel design as the 737 Max 9, which had 171 planes in its fleet grounded after a door panel on one of the planes blew off shortly after a flight of Alaska Airlines will take off from Portland, Oregon, in January. 5., which forced an emergency landing.
Door plugs are placed as a panel where an emergency door would otherwise be if a plane had more seats.
The federal aviation safety agency later grounded the 737 Max 9 fleet and announced it was investigating whether Boeing failed to ensure the plane was safe and conformed to the agency's approved design.
The FAA said Sunday that the door plug on the 737-900ER, which is not part of the Boeing Max line, has not yet been an issue.
“As an additional layer of safety, the Federal Aviation Administration recommends that operators of Boeing 737-900ER aircraft visually inspect intermediate exit door plugs to ensure the door is properly secured,” the agency said in a statement.
The FAA recommends that airlines using the Boeing 737-900ER immediately inspect the four locations used to secure the door plug to the fuselage. The Boeing 737-900ER has more than 11 million operating hours and about four million flight cycles, according to the FAA
“We fully support the FAA and our customers in this action,” Boeing said in a statement.
Alaska Airlines, United Airlines and Delta Air Lines, which use the 737-900ER, said in statements that they had already begun reviewing door plugs in their fleet. None of them expect any disruptions to their operations.
The incident involving Alaska Airlines Flight 737 Max 9 earlier this month did not result in serious injuries, but could have been much more serious if it had occurred when the plane was at its cruising altitude. The National Transportation Safety Board is investigating the incident in hopes of learning what caused the door plug to be ejected from the plane.
Meanwhile, the FAA recently ordered an initial round of inspections of 40 of the Boeing 737 Max 9 planes on the ground as it works to develop final inspection instructions for the planes.
